The 51 mm stroked version of our BGM crankshafts which is perfectly suited for the ESC racing series or ambitioned road riding. The larger diameter of the crank webs from the 54mm crank has been kept to allow a larger overlap for the big end bearings. This allows additional safety against the crank twisting.
In order to fit the larger diameter crank webs (87 mm on the flywheel side and 86 mm on the drive side) you have to machine the casings to 88 mm.
This enables you to fit the 54 mm crankshaft for even more power later on, if desired. The next innovative feature is the piston rod length which has been increased to 105 mm (8 mm longer than on standard 125 cc Smallframe cranks).
The crank is a perfect fit to some of the latest Smallframe tuning kits that are designed to be run with this sort of piston rod.
An easy way to use it with every other barrel available, is to fit the 8 mm bgm spacer (BGM0223) and longer cylinder stuts (BGM 0290). Also available as complete kit (7673185
). Upshot: a better angle, which is perfect for the life of the big end bearing and reduced friction of the piston in the bore hole.
This results in better power and reduced primary compression, which work well with the modern day exhausts, such as the ones made by manufacturer Ludwig and Scherer, as the port transfers at the casing can be improved and the flow optimized.
-strong crank webs
-less twisting danger
-higher primary compression
-less stress in piston and bearings